#include <iostream>
using namespace std;
int main() {
int mas [10000], n, i, j, a[10000];
cin >> n;
for (i = 0; i < n; i++)
cin >> mas[i];
for (i = 0; i < n; i = i + 3) {
a [j] = mas [i];
j++;
}
for (i = 0; i < j; i++)
cout << a [i] << " ";
}
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